i.u-tokyo.ac.jp

Email infrastructure report · Last checked 28 Jul 2026, 16:30 UTC

Summary

i.u-tokyo.ac.jp uses Self-hosted / Custom for email and has SPF configured. It is not catch-all.

Mail provider

ProviderSelf-hosted / Custom self-hosted

Primary MXnew-istmail.i.u-tokyo.ac.jp

MX records

Priority	Hostname	IPs
10	new-istmail.i.u-tokyo.ac.jp	133.11.235.11, 2404:d540:1:2041:be24:11ff:fe89:fdc8

Authentication

SPF✓ Present -all

DKIM? Not detected via common selectors

DMARC✗ Missing

Raw SPF record

v=spf1 +ip4:133.11.0.0/16 +ip4:157.82.0.0/16 +ip4:130.69.0.0/16 +ip6:2404:d540:1:2041::/64 -all

Email behavior

Catch-all✗ No

Disposable✗ No

Free provider✗ No

STARTTLS? Could not determine (connection refused)

SMTP response—

SMTP banner—

What this means

This domain is missing DKIM, DMARC, which weakens its protection against email spoofing. Adding these records would improve deliverability and reduce the risk of impersonation.

Refresh this report

Cached results are kept indefinitely. If you think the data above is out of date, run a fresh check below. Refreshes are rate-limited (1 per domain every 5 minutes).

Want to verify individual addresses at i.u-tokyo.ac.jp?

CheckMail's API verifies real-time deliverability with SMTP checks, not just DNS lookups. 100 free credits, no credit card required.

Get an API key →

curl https://api.checkmail.dev/v1/verify \
  -G --data-urlencode "email=test@i.u-tokyo.ac.jp" \
  -H "Authorization: Bearer cm_live_..."